"If you talk to most air travelers ... traveling on the airlines is about as popular as the U.S. Congress right now," said Brandon Macsata, a spokesman for the group.

Here is what you need to know about the Department of Transportation's new protections:

Bumping compensation gets a boost

Passengers involuntarily bumped from oversold flights are now eligible for more money.

Under the new rule, bumped passengers can get up to $650 if the airline can get them to their destination within a short period of time (within one to two hours of their originally scheduled arrival time for domestic flights), or up to $1,300 if they are delayed for a long time.

Before Tuesday, the amounts were capped at $400 and $800 respectively.

Inflation adjustments will be made to the compensation limits every two years.

Always take cash rather than flight vouchers, Hanni advised.

"Vouchers come with a lot of caveats. Anytime the airline offers you a voucher, it's to their benefit, not yours," Hanni said.

"If they give you a $1,300 voucher, it's worth about a quarter of that to the airline as opposed to having to give you cash."

International flights get tarmac delay limit

International flights stuck on U.S. airport tarmacs more than four hours must now allow passengers to get off the plane or face huge fines, with exceptions allowed for safety, security or air traffic control-related reasons.

Macsata called it a step forward, but said he would have preferred for this protection to be consistent with the three-hour rule that already exists for domestic flights.

The domestic provision has significantly reduced the number of lengthy tarmac delays since it was implemented last year. Fourteen flights were stuck on the tarmac for three hours or more in June, compared to 268 flights in June 2009, according to the Bureau of Transportation Statistics.

But Hanni said the extra hour allowed for international flights is still an improvement.

"Four hours is a heck of a lot better than 12 and we've had a lot of complaints from people who sat for 12 hours on international flights prior to takeoff or after landing," Hanni said. "So we're making headway, that's a huge deal."

International airlines operating to and from the United States must now post contingency plans for lengthy delays, customer service plans and contracts of carriage on their websites.

Bag fee refunds

If you pay extra to check a piece of luggage and the airline loses your bag, it must now refund the bag fee. (Airlines already must compensate passengers for lost or damaged baggage.)

"That's just common sense," Macsata said.

Hanni also wanted the airlines to be required to refund the fee if your bag is delayed, but wasn't successful in having that provision included.

Where refunds are due, airlines must now provide prompt refunds of fares and optional fees.